## King 3 years ago xy+x+y=-13 yz+y+z=-9 xz+x+z=5 Find x,y,z.

1. Lumenaire

x(y+1) + y = -13 so x = (-13 -y)/(y+1)

2. Lumenaire

substitute that in for x, and the rest is just a simple 2 equations with 2 unknown variable problem

3. King

4. Lumenaire

try.

5. King

what is -13-y*z+1?

6. Lumenaire

can you be more clear? post your work

7. King

wait i got (-13z-13-yz-y)/y+1 +z=5

8. Lumenaire

ok use equation 2 now: y(z+1) + z = -9 so y = (-9-z)/(z+1) plug that in for y

9. King

i got z^2+2z=3

10. Lumenaire

ok. that is a quadratic equation. solve it

11. King

can z hav 2 values?

12. Lumenaire

yes

13. King

then ans is 1,-3

14. King

for z

15. Lumenaire

correct

16. Lumenaire

now substitute for z in the other equations

17. Lumenaire

(for simplicity's sake, substitute into the original equations)

18. King

ok ,y =-5,3

19. Lumenaire

correct

20. King

x=-4,2

21. Lumenaire

there you go. That's it!

22. King

thnx....ure awesome!!!!!!!!!!!!!

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